Comprehensive Guide to Inserts in CNC Machining

CNC (Computer Numerical Control) machining technology plays a pivotal role in modern manufacturing, and inserts, as a key tool in CNC machining, directly impact machining efficiency and product quality. This article will detail the types, materials, machining methods, coatings, advantages, hardness, and lifespan of inserts.

Types of Inserts

1. Turning Inserts: Mainly used for turning operations, suitable for external, internal, and face turning.
2. Milling Inserts: Used for milling operations, including face milling, end milling, and slot milling.
3. Drilling Inserts: Specialized for drilling operations, commonly used in twist drills and center drills.
4. Boring Inserts: Used for precise internal hole machining, suitable for high-precision boring operations.

Materials of Inserts

1. Carbide: A common insert material with good wear resistance and hardness, suitable for machining most metal materials.
2. Ceramic: Extremely hard and high-temperature resistant but brittle, suitable for high-hardness materials and high-speed cutting.
3. Diamond (PCD): Suitable for machining non-metallic materials such as aluminum alloys and composites, with extremely high hardness and wear resistance.
4. Cubic Boron Nitride (CBN): Specialized for machining high-hardness ferrous materials like hardened steel and cast iron.

Machining Methods for Inserts

1. Turning: Cutting by the relative motion of the rotating workpiece and the stationary tool.
2. Milling: Cutting by the rotating tool and moving workpiece through multi-edge tools.
3. Drilling: Rotating tool, stationary workpiece, primarily used for hole machining.
4. Boring: Precision internal hole machining by the rotating tool.

Coatings of Inserts

1. Titanium Nitride (TiN): Increases surface hardness and wear resistance, suitable for various materials.
2. Titanium Carbonitride (TiCN): Higher hardness than TiN, stronger wear resistance, suitable for high-speed cutting.
3. Aluminum Oxide (Al2O3): Good stability at high temperatures, suitable for high-temperature cutting environments.
4. Aluminum Titanium Nitride (AlTiN): Excellent thermal hardness and wear resistance, suitable for dry cutting and high-temperature environments.

Advantages of Inserts

1. Efficient Machining: Increases machining efficiency and reduces production time.
2. High Precision: Ensures dimensional and shape accuracy of machining.
3. Long Lifespan: High-quality inserts have a long lifespan, reducing replacement frequency.
4. Versatility: Suitable for various machining methods and materials.

Hardness of Inserts

The hardness of inserts is a key indicator of their wear resistance and cutting capability. Carbide inserts generally have a hardness between HRA 89-93, ceramic inserts have higher hardness, typically between HRA 93-95, while PCD and CBN inserts can reach hardness above HRA 95.

Lifespan of Inserts

The lifespan of inserts depends on their material, coating, and machining conditions. Generally, carbide inserts have a lifespan ranging from tens to hundreds of hours, ceramic inserts can last longer under appropriate conditions, and PCD and CBN inserts have extremely long lifespans, especially in machining high-hardness materials.

Choosing the right tool inserts is the key to ensure the quality and efficiency of CNC machining. Understanding the tool inserts can help us to better tool management and improve machining efficiency.